Per the Prusa Slicer Knowledge Base…
Skirt
The skirt is a printed outline of all of the models on the print bed. It’s printed before any of the models and its purpose is mainly to stabilize the flow of the filament through the nozzle.
The skirt is also useful to verify the adhesion of the first layer to the print bed. Since it’s printed before the models, you can quickly change the Live Z adjust if you see the first layer not sticking properly or being too squished by the nozzle.
Can someone tell me in layman’s terms, if skirts are needed with the X1C since you can already tell if you have good adhesion with the flow calibration and other filament it lays down before it starts printing?